JP4386985B2 - In-vehicle measuring device for road surface extension - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-vehicle measuring apparatus that can obtain a highly accurate measurement result by finely calculating the shape of a road surface in the extending direction from a vehicle attitude and vehicle height sensor measurement data based on a relatively simple arithmetic expression.
[0002]
[Prior art]
Conventionally, a cross-sectional profile, a vertical cross-sectional profile, and a crack of a road surface are measured by a measuring device mounted on the vehicle in order to grasp the road surface property. For example, according to Japanese Patent Laid-Open No. 10-168810, distance measuring means for measuring the distance of a vehicle to a road surface, vertical acceleration measuring means for measuring acceleration in the vertical direction, and acceleration measured by the vertical acceleration measuring means. Integrating means for obtaining a displacement in the vertical direction by integrating the above, attitude measuring means for measuring the attitude angle of the vehicle, attitude angle measured by the attitude measuring means and distance measured by the distance measuring means A vehicle is equipped with a measuring device having a means for calculating a vertical distance to the road surface, and using the difference between the calculated vertical distance and the displacement obtained by the integrating means to obtain the longitudinal profile. The road profile of the road is measured.
[0003]
As the distance measuring means, for example, laser light or ultrasonic waves are used, and the distance between the vehicle and the road surface is measured by detecting the reflection. In addition to the triaxial gyro, the attitude measuring means uses a triaxial accelerometer, GPS, or a speed sensor instead of GPS. The X, Y, and Z accelerations output from the three-axis accelerometer are converted into accelerations of respective coordinates of N (north direction), E (east direction), and D (center direction of the earth) that are inertial coordinates by coordinate conversion means. These N, E, and D accelerations are integrated to determine each speed, and the N, E, and D speeds are further integrated to calculate vertical displacement H and N, E positions (movement distances). The increase in error due to the integration of the N and E positions obtained by integrating the N and E velocities is corrected by comparing with the N and E positions of GPS, for example.
[0004]
According to the profile measuring apparatus for a longitudinal section of a road disclosed in this publication, in addition to measuring the unevenness of the road surface such that the vehicle body moves up and down with respect to the road surface, the road surface where the vehicle body runs along the road surface with an inclination. Therefore, it is possible to accurately measure the vertical undulations of the road, so that an accurate road profile can be obtained.
[0005]
[Problems to be solved by the invention]
In other words, the method for measuring the profile of the longitudinal section of the road is based on the vertical vertical displacement obtained from the three-axis accelerometer and the three-axis gyro, and each data obtained by the roll angle, the pitch angle, the gyro mounting height, and the distance measuring means between the road vehicles. The value obtained by subtracting the height in the vertical direction obtained by calculating from is used as the road profile. For this reason, the data obtained depends on the accuracy of vertical vertical displacement by the three-axis gyro, but this vertical vertical displacement changes to the acceleration obtained by the three-axis accelerometer. Using the Z angular acceleration data, the matrix change is updated and input to the coordinate conversion means. Then, the vertical acceleration output from the coordinate conversion means is double-integrated (converted into velocity and then converted into displacement) to calculate the vertical vertical displacement, and thus various problems as listed below. Occurs.
[0006]
(1) In order to reduce the divergence of 3-axis gyro data generated by integration, it is necessary to use a high-pass filter as described in the above publication. In this case, the accurate road surface waviness period of the longitudinal profile obtained by the frequency range to be adopted is limited, and it is impossible to measure a gentle slope. For example, if the cut-off frequency of the high-pass filter is 0.4 Hz or less, a road surface waviness period of 69 m or more cannot be measured from a vehicle traveling at a speed of 100 km / h.
[0007]
(2) When the vertical acceleration is double-integrated to determine the displacement, the change in the vertical acceleration of the vehicle is limited to alternating sine wave motion with a frequency exceeding 0.4 Hz. When the acceleration changes at a frequency of 0.4 Hz or less, the displacement output converges to zero with time.
[0008]
(3) On the other hand, when trying to correct the output (roll angle, pitch angle, vertical vertical displacement) data of the 3-axis gyro based on the data from GPS, the data from GPS is generally obtained only at intervals of 1 sec. In order to obtain highly accurate data using these data, only output data from a three-axis gyro corrected at intervals of 1 sec can be employed. Therefore, for example, if data for use in a longitudinal profile with high reliability is obtained from a vehicle having a vehicle speed of 36 km / h, only data at intervals of 10 m can be employed. This means that only measurement under limited conditions is effective in a measurement vehicle traveling on an actual road surface.
[0009]
(4) Furthermore, the vertical vertical displacement component of the gyro installed on the vehicle consists of harmonic components superimposed on each vertical vertical displacement component including road surface shape, vehicle tire, spring system, and 0.4 Hz. Since it cannot be the above AC sine wave motion, accurate measurement cannot be expected.
[0010]
The present invention has been made to solve the above-described problems in the conventional measuring apparatus of this type, and specifically, it is possible to easily swell road surfaces from a very short distance to a relatively long distance. An object of the present invention is to provide an in-vehicle measuring device having a road surface extending direction shape that can be accurately measured using an arithmetic expression.
[0011]
[Means for solving the problems and effects]
In order to achieve the above-mentioned object, the present inventors have examined what factors cause the above-described problem of the measuring device disclosed in the above publication. In the measuring device according to the publication, the vertical change that changes every moment as described above is used to calculate the amount of matrix change using the Z-axis angular acceleration data of the 3-axis gyro as the Z acceleration obtained from the 3-axis accelerometer. The vertical acceleration is obtained from the value and is calculated by double integration. In order to avoid error divergence due to double integration at this time, a high-pass filter is interposed as described above. Due to the high-pass filter, measurement conditions are limited.
[0012]
The invention according to claim 1 is provided with an inclination angle detecting means for measuring a rolling angle (α) and a pitching angle (β) of the vehicle, and both ends on the same straight line in the width direction of the vehicle. Vehicle height detection means for measuring Am, Bm), travel distance detection means for measuring the distance in the traveling direction of the vehicle, and various measurements detected by the detection means for each predetermined distance (L). It has a sampling means for sampling data and a scanner that scans a laser beam on the road surface. By inputting the measurement data,
Rθ _i = tan ⁻¹ (b _i / l)
= Tan ^-1 [{ _HiL- ( _{HiR- ai} )} / l]
h _{i + 1} = Lsin β _i
However, R.theta _i: cross slope angle of a road surface of each measurement point
l: Distance between left and right vehicle height detection means
a _i : l · tan α _i (relative vehicle height at one end in the vehicle width direction)
b _i : H _iL − (H _iR −a _i ) (relative vehicle height at the other end in the vehicle width direction)
h i _{+ 1:} the road surface height difference between the previous measurement point P _i at the measurement point P _{i + 1}
i: 0 to n (sampling times)
An in-vehicle measuring device for extending in the road surface direction has an extending direction shape calculating means for performing a crossing gradient calculation and a longitudinal gradient calculation in the road surface extension direction based on the above equation.
[0013]
Always using the previous (i-th) measurement point P _i as a reference point, the road surface crossing gradient Rθ _i and the measurement point P at the next (i + 1) -th measurement point P _{i + 1} when the vehicle travels a predetermined distance L. the height difference H _{i + 1} between the previous measurement point P _i in the _{i + 1,} each value using the arithmetic expression measurement data is input to the arithmetic apparatus mounted on a vehicle at the measurement point P _{i + 1} The profile of the road to the next measurement point P _{i + 1} with the previous measurement point P _i as the reference point is calculated. In the next calculation, the road surface crossing gradient Rθ _{i + 2} and the same measurement at the next measurement point P _{i + 2} separated by a predetermined distance L on the road surface extension with the measurement point P _{i + 1} as a new reference point. The height difference H _{i + 2} between the point P _{i + 2 and} the previous measurement point P _{i + 1} is obtained according to the above equation. By repeating this operation, the longitudinal profile of the road surface for each distance L is measured.
[0014]
According to the present invention, since the distance L for sampling set in advance can be determined arbitrarily, it is possible to measure with sufficient accuracy in practice by selecting a distance that is less affected by disturbances, and The calculation formula is only a purely geometric calculation formula between two measurement points that is updated sequentially every measurement, and no special operation such as integration is required. A longitudinal profile that is accurate relative to the previous measurement for each set distance L can be measured. In addition, correction by GPS data is unnecessary for normal measurement, but if absolute elevation of the road surface is required, it is based on absolute elevation using GPS elevation data for the measurement data. It is also possible to calculate the cross section gradient and the vertical section gradient.
[0015]
The invention according to claim 2 sets the predetermined distance (L) which is a sampling interval in a range of 20 to 30 cm. There is an International Roughness Index (IRI) as an index for associating flatness indexes obtained from various road surface roughness measuring devices with each other and grasping a uniform road surface roughness. This IRI is an average value of the amount of change in the mutual displacement of the vehicle body and the wheel at every sampling interval of the longitudinal profile (the corrected slope of the road surface) with respect to the entire longitudinal profile, and is obtained for each extension of the longitudinal profile. The interval is determined to be 25 cm in consideration of the tire envelope characteristics, and the standard vehicle speed is 80 km / h. From this point of view, in the present invention, the sampling interval (L) is set between 20 and 30 cm according to the vehicle speed of the measuring vehicle of 60 to 100 km / h.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings.
FIG. 1 schematically shows an arrangement when measuring devices according to the present invention are mounted on a vehicle. Right and left vehicle height sensors 4R and 4L are fixedly provided at predetermined vertical intervals directly above the right and left straight lines connecting the front and rear contact points of the right and left front wheels 2R and 2L and the rear wheels 3R and 3L. is doing. In the illustrated example, an inclinometer 5 is fixed at the center of a straight line connecting the right and left vehicle height sensors 4R and 4L, and a travel distance sensor 6 is attached to the right rear wheel 3R so as to rotate. As the vehicle height sensors 4R and 4L, known optical sensors or ultrasonic sensors are used, and for the inclinometer 5, various gyros are used.
[0017]
Further, in the present embodiment, the measurement vehicle 1 has a laser head 7 and a laser beam emitted from the head 7 on a straight line perpendicular to the traveling center line of the vehicle 1 on the road surface in front of the vehicle 1. A scanner 8 for scanning the beam is mounted, and rudder sensors 9R and 9L for detecting the rubbing and cracking state of the road surface by receiving reflected light of the road surface on the scanning line of the laser beam on the front surface of the vehicle 1 and cracks. Sensors 10R and 10L are attached. The rutting sensors 9R and 9L and the crack sensors 10R and 10L are provided on the left and right sides in order to share the detection of the left and right half portions of the road surface.
[0018]
FIG. 2 is a flowchart showing an example of a method for measuring the shape of the road surface in the extension direction by the measuring apparatus according to the present invention. FIG. 3 is an explanatory diagram of a method for measuring the cross gradient of the road surface. FIG. FIG. However, in the same figure, detection procedures such as waviness in the transverse direction of the road surface by the rutting sensor 9 and the crack sensor 10 are omitted.
Note that the calculation of data by the sensors arranged on the left and right of the measurement vehicle 1 is performed for each of the right and left, but the calculation procedure is not different between the right and left, so the following description will explain one calculation procedure. I will decide.
[0019]
According to FIG. 2, first, the distance (vehicle height) H _0R and H _0L from the road surface to each sensor 4R and 4L is measured by the vehicle height sensors 4R and 4L at the first measurement point P ₀ , and the vehicle is measured by the inclinometer 5 The rolling angle α ₀ and the pitching angle β ₀ are detected. Of these data, the calculation device 11 is equipped with the vehicle height H _0R and H _0L data from the left and right road surfaces to the vehicle height sensors 4R and 4L, and the rolling angle α ₀ and pitching angle β ₀ of the vehicle. Entered in
a _i = l · tan α _i (relative vehicle height at one end in the vehicle width direction)
_{b i = H iL - (H} iR -a i) ( relative vehicle height in the vehicle width direction end)
Rθ _i = tan ⁻¹ (b _i / l)
= Tan ^-1 [{ _HiR- ( _{HiL- ai} )} / l]
h _{i + 1} = Lsin β _i
Where Rθ: road surface gradient angle l: distance between left and right vehicle height detection means a _i : l · tan α _i (relative vehicle height at one end in the vehicle width direction)
_{b i: Bi- (Ai-a} i) ( relative vehicle height in the vehicle width direction end)
h _{i + 1:} the road surface height difference i the last of the measuring point P _i at the measurement point P _{i + 1:} 0~n (sampling times)
The vehicle height is corrected using the above arithmetic expression, and the relative heights a ₀ and b ₀ (where L is 0) with respect to the respective road surfaces at the left and right ends of the vehicle 1 are obtained.
[0020]
Next, assuming that the distance between the vehicle height sensors 4R and 4L is l, the arithmetic unit 11 calculates the road surface cross-gradient angle Rθ ₀ from the relative heights a ₀ and b ₀ using the following equation, and the road surface Is obtained and stored in the storage unit 12.
[0021]
Subsequently, the measurement vehicle 1 is caused to travel a preset distance L, and the left and right sides of the vehicle 1 at the second measurement point P ₁ are set with reference to the relative heights a ₀ and b ₀ of the first measurement point P _0. The relative heights a ₁ and b ₁ with respect to the road surface at both ends are calculated using the above-described arithmetic expressions, and the road surface height difference between the previous measurement point P ₀ and the second measurement point P _{1 at} the left and right ends of the vehicle 1 is calculated. h ₁
Formula h ₁ = Lsin β ₀
Calculate using.
[0022]
In the present embodiment, the distance L is set to 25 cm, and the distance is extremely short. Therefore, the first longitudinal gradient angle is assumed to be equal to the pitching angle β ₀ at the first measurement point P ₀ detected by the inclinometer 5. handle. The relative heights a ₁ and b ₁ with respect to the road surfaces at the left and right ends of the vehicle 1 at the second measurement point P ₁ thus obtained, and the previous measurement point P ₀ and the second measurement point P _{1 at} the right and left ends of the vehicle 1 are obtained. From the road surface height difference h ₁ , the cross-sectional shape and the vertical cross-sectional shape of the second measurement point P ₁ are determined, and the extension shape of the road surface is determined. By repeating the above sampling and calculation operations, the third to n-th measurements are sequentially performed, and the road surface shape in the extending direction is measured as shown in FIG.
[0023]
6 (a) and 6 (b) show the state of change in the road surface extension direction written by plotting the actual measurement values obtained by leveling, and the state of change in the road surface extension direction based on the calculation result by the device of the present invention. FIG. From these figures, it can be understood that the calculation result by the device of the present invention approximates the actual measurement value.
[0024]
As can be understood from the above description, according to the measuring device for the shape of the road surface extension direction according to the present invention, since the integral calculation is unnecessary in calculating the cross-sectional profile and the vertical cross-sectional profile in the road surface extension direction, There is no divergence of data error, and the measurement sampling interval (L) can be set arbitrarily, so that the measurement error can be reduced, and high-accuracy measurement is possible from short undulation to long period undulation in the road surface extension direction. . Further, when the vertical vertical displacement is inaccurate, or when radio waves from a satellite cannot be received by a building or a standing bridge and GPS data cannot be obtained, the shape in the extension direction can be measured.
[0025]
Further, according to this embodiment, the laser beam is scanned on the road surface orthogonal to the traveling direction of the vehicle, so that the undulation in the width direction of the road surface is sequentially measured. Therefore, more accurate road surface properties are measured. obtain. As a result, a three-dimensional shape of the road surface is obtained, and the rutting data of the measurement vehicle of the road surface property of the present invention is corrected with the calculation result of the cross slope, and accurate by connecting it to the vertical slope calculation result (extension direction shape). A smooth three-dimensional shape of the road surface can be obtained, and road surface data and the like can be used for calculating the amount of construction during road repair and evaluating the ride comfort of the vehicle. Note that the measurement of the undulations in the width direction of the road surface (the form of rutting or cracking) can be performed by, for example, a measuring apparatus proposed in Japanese Patent Application Laid-Open No. 61-112918.
[0026]
Furthermore, in the present invention, height correction can be performed using vertical vertical displacement and GPS data. Specifically, the relative road surface height difference H ₁ calculated as described above is corrected for altitude using GPS altitude data, and the absolute altitude level is reduced as shown in FIGS. 7 (a) and 7 (b). A difference can also be obtained, which is effective in creating a three-dimensional map, for example.
[Brief description of the drawings]
FIG. 1 is a layout view of various sensors of a vehicle equipped with an extension direction shape measuring device of the present invention.
FIG. 2 is a flowchart showing a calculation procedure by the apparatus of the present invention.
FIG. 3 is an explanatory view showing an example of a method for calculating a crossing gradient angle of a road surface by the device of the present invention.
FIG. 4 is an explanatory diagram for obtaining an extension direction shape by the apparatus of the present invention.
FIG. 5 is an explanatory view showing the shape in the extension direction of the road surface obtained by connecting the height differences of each measurement point obtained by the device of the present invention.
FIG. 6 is a contrast diagram obtained by plotting measured values obtained by leveling and calculated values obtained by the device of the present invention.
FIG. 7 is a diagram showing the difference in elevation in the road surface extension direction obtained by correcting relative height difference data by the apparatus of the present invention using GPS data, in comparison.
[Explanation of symbols]
1 Measurement Vehicles 2L, 2R Left and Right Front Wheels 3L, 3R Left and Right Rear Wheels 4L, 4R Left and Right Vehicle Height Sensor 5 Inclinometer 6 Travel Distance Sensor 7 Laser Head 8 Scanner 9L, 9R Left and Right Rutting Sensors 10L, 10R Left and Right Cracks Sensor 11 Computing device

Claims (2)

A tilt angle detecting means (5) for measuring a rolling angle (α _i ) and a pitching angle (β _i ) of the vehicle;
A pair of left and right vehicle height detection means (4L, 4R) installed at both ends on the same straight line in the width direction of the vehicle and measuring the distance ( _HiL , _HiR ) to each road surface;
Mileage detection means (6) for measuring the distance in the traveling direction of the vehicle;
Sampling means for sampling various measurement data detected by each of the detection means at a predetermined distance (L) set in advance;
With the input of the measurement data, an extension direction shape calculation means (11) for performing a crossing gradient calculation and a longitudinal gradient calculation in the road surface extension direction based on the following calculation formula,
A scanner (8) for scanning a laser beam on the road surface;
A vehicle-mounted measuring device having a shape extending in the road surface direction.
Rθ _i = tan ⁻¹ (b _i / l)
= Tan ^-1 [{ _HiL- ( _{HiR- ai} )} / l]
h _{i + 1} = Lsin β _i
However, R.theta _i: cross slope angle of a road surface of each measurement point
l: Distance between right and left vehicle height detection means
a _i : l · tan α _i (relative vehicle height at one end in the vehicle width direction)
b _i : H _iL − (H _iR −a _i ) (relative vehicle height at the other end in the vehicle width direction)
h i _{+ 1:} the road surface height difference between the previous measurement point P _i at the measurement point P _{i + 1}
i: 0 to n (sampling times) The in-vehicle measurement device according to claim 1, wherein the predetermined distance (L) is in a range of 20 to 30 cm.

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